d-block & transition metals Flashcards
1
Q
Define d-block element
A
- d electrons in outer shells
- d-block elements have similar e config
2
Q
Order of filling/removing e
A
- 4s before 3d
- energy of 4s lower than 3d
- once 3d shell is filled, 4s e are repelled further away frm nucleus
- 3d subshell lower in energy than 4s shell after being filled
- 4s removed first
3
Q
Energies of 4s and 3d
A
- almost equal
4
Q
Typical physical properties
A
- gd conductors (heat, electricity)
- malleable
- ductile
- lustrous
- hard, strong
- high mp and bp
5
Q
Transition elements
A
- d-block element
- forms at least one stable ion
- partially filled d-orbitals (incomplete d sublevels)
- not all d-block elements are transition elements
6
Q
Density (s-block metals vs transition)
A
- transition metals denser than s-block
- transition metals: smaller atomic radius, close packed
- high relative atomic mass
- atoms pulled closer tgt
- higher mass per unit vol
- higher density
7
Q
MP&BP
A
- transition metals have higher mp&bp than s-block
- giant metallic structure
- overcomes stronger electrostatic forces of attractions % cations and delocalized sea of e
- larger no. of 3d and 4s e involved in delocalization
- cations of higher charge formed
- larger amt of energy needed
8
Q
Mechanical qualities (s-block vs transition)
A
- transition elements – high tensile strength, malleability, ductility
- layers of closely packed atoms easily slide over one another
- w/o disrupting electrostatic attraction % cations and sea of delocalized e
9
Q
Electrical and thermal conductivity (s-block vs transition)
A
- transition – btr thermal and electrical conductors than s-block
- both 3d and 4s available for delocalization
10
Q
Chemical properties of transition elements
A
- Form variable oxidation states in their compounds
- Coloured compounds and ions
- Show catalytic activity
- Form stable complexes
- Form paramagnetic compounds
11
Q
Variable oxidation states
A
- O.S: no. of e lost or gained frm original state
- 3d and 4s orbitals – close in energies
- variable number of 4s and 3d can be removed to form ions of similar stability
